Change icon SVG imports to use a default import (#28709)

app/javascript/__mocks__/svg.js

app/javascript/mastodon/components/attachment_list.jsx

app/javascript/mastodon/components/badge.jsx

app/javascript/mastodon/components/column_back_button.tsx

app/javascript/mastodon/components/column_header.jsx

app/javascript/mastodon/components/copy_icon_button.jsx

app/javascript/mastodon/components/dismissable_banner.tsx

app/javascript/mastodon/components/domain.tsx

app/javascript/mastodon/components/dropdown_menu.jsx

...javascript/mastodon/components/edited_timestamp/index.jsx

app/javascript/mastodon/components/icon.tsx

app/javascript/mastodon/components/load_gap.tsx

app/javascript/mastodon/components/media_gallery.jsx

...pt/mastodon/components/picture_in_picture_placeholder.jsx

app/javascript/mastodon/components/poll.jsx

app/javascript/mastodon/components/status.jsx

app/javascript/mastodon/components/status_action_bar.jsx

app/javascript/mastodon/components/status_content.jsx

app/javascript/mastodon/components/verified_badge.tsx

app/javascript/mastodon/components/visibility_icon.tsx